Introduction

Bakelite, also known as phenolic molding compound, is a type of thermoset plastic widely used in industrial and household products due to its high mechanical strength, stable performance, acid and alkali resistance, and excellent high and low temperature resistance. Hitech specializes in bakelite, BMC and precision plastic injection molding, and we will introduce our standardized bakelite injection molding process in detail as follows.

Hitech’s Bakelite Injection Molding Process

1. Material Preheating & Plasticization

Bakelite injection materials are usually in powder form. In the barrel of the injection molding machine, the thermoset plastic is heated by the barrel heating device and friction generated by the screw rotation. This dual heating effect melts the material and achieves pre-plasticization, preparing it for the subsequent injection process.

2. Mold Heating

Unlike ordinary plastic molds, bakelite molds require a long heating time before production. Sufficient mold heating ensures that the molten material can maintain a high temperature during injection, promoting a complete cross-linking reaction and ensuring the structural stability of the final product.

3. Injection of Bakelite Products

After pre-plasticization is completed, the mold is closed, and the screw starts to inject. The molten material is pushed by the screw to flow through the main channel, runner and gate of the mold, and finally fills the entire cavity. Due to the shear heat generated during injection and the high temperature of the mold, the temperature of the molten material rises rapidly and enters a rapid reaction state. Notably, the injection time of bakelite products is longer than that of ordinary plastic products.

4. Pressure Holding & Curing

Immediately after injection, the process enters the pressure holding stage. The purpose of pressure holding is twofold: first, to compensate for material shrinkage; second, to ensure the product has a compact and solid structure. After pressure holding, a delay period is required to wait for the material to be completely cured and the product to be fully shaped.

5. Product Ejection & Mold Cleaning

Once the product is fully cured, the mold is opened, and the finished bakelite product is ejected. After ejection, the mold is cleaned to remove residual material and prepare for the next production cycle.